Here's another interesting SIN fare fact: The cheapest business class fare UA offers SFO-SIN (PFXT2UMF) has no advance purchase requirement. So UA uses inventory restrictions in lieu of an AP requirement to keep prices high for last second purchasers, meaning that with 16 open J seats at T-48, Thursday night's flight is D8 Z0 P0. I'm hoping to SDC my P fare, currently routed SFO-LAX-SIN, to the nonstop, but looks like this may not be possible.